I use West Riding multipurpose for sowing too and this year’s mix is especially good for that, being lighter. I do not worry about acidity, any supplier of peat based compost will have checked that.
Just to avoid confusion, their term "Moorland Gold" is describing the (recycled) peat only, which they sell like that with no additives if you want just the base.
I have struggled to find a good seed compost and always reckon that a good multipurpose should live up to its name. Last year I had good success with sowing into pure cow manure! Good luck with whatever you use.